Various hand tools employ operating members which are pivotably assembled, and some of these utilize springs to bias the handles apart so that the user closes the jaws by applying clamping pressure to the handles. In order to maintain the jaws and handles in a closed position for storage and for preventing injury to any of the working surfaces thereof, as well as possible injury to users of the tool during transport or storage thereof, various latches have been devised to maintain the handles in a closed position.
Frequently, such latches employ separate elements which are mounted upon the handles in a manner permitting pivotal movement of one or both thereof. In some instances, a projection may be integrally formed in one of the handles and a separate latch mounted upon the other of the handles for pivoting into engagement with the shoulder as, for example, in Koblick Design U.S. Pat. No. 238,650 granted Feb. 3, 1976; Stevenson Design U.S. Pat. No. 239,080 granted Mar. 9, 1976; and Streight U.S. Pat. No. 803,796 granted Nov. 7, 1905.
With the advent of sythetic resins such as polypropylene and propylene polyallomers providing integral self-hinging characteristics, there have been recent efforts to provide latches wherein both elements are integrally formed from the synthetic resin of the handle members. Illustrative of such a structure is Ferguson U.S. Pat. No. 3,869,793 granted Mar. 11, 1975.
It is an object of the present invention to provide a hand tool such as shears and the like employing a novel and highly effective latch assembly wherein the components thereof are integrally formed with synthetic resin handles and wherein such components may be readily engaged and disengaged.
It is also an object to provide such a hand tool wherein the components of the latch assembly are rugged and durable and may be readily fabricated at the time of molding of the synthetic resin handles.
Another object is to provide such a hand tool wherein pivoting of one latch component relative to the other produces a camming movement to effect the latching and wherein additional movement of the handles in the closing direction will disengage the latch assembly.